Saturday, March 30, 2013

Extending you home, small business, data center, co lo, or enterprise offices to AWS running VPC, you will probably want to run an IPSEC tunnel. AWS lists the certified VPN devices here: http://aws.amazon.com/vpc/faqs/#C9. However, if you are doing this from a home or small office connection, you may not want to use an expensive dedicated device. In this case the open source pfSense makes sense: www.pfsense.org. It can used to create an inexpensive IPSEC tunnel to AWS VPC using any hardware you have 'laying around'.

Thursday, March 28, 2013

Because Oracle databases are typically terabytes in size and required 1000's of IOPS, you will typically use EBS PIOPS volumes with EBS-optimized EC2 instances. This leads the often asked question of "What does EBS optimized EC2 instances really mean?" The short answer is that storage pipe to the EBS (PIOPS) volume is dedicated and does not compete with network traffic like it does in a non EBS-optimized instance. A more detailed answer can be found here:http://perspectives.mvdirona.com/2012/08/01/EBSProvisionedIOPSOptimizedInstanceTypes.aspx

Friday, March 22, 2013

As enterprise began to move to the cloud, the question of running very large Oracle databases on AWS is coming up. Of course, the definition of a what is a VLDB varies by industry, size of company, and personal opinion. For our discussion, let's say it is a 10's of TB database. In this case, most Oracle databases of this size will be running on Oracle RAC. Currently, Oracle RAC is not supported on AWS.

A method to get around the lack of support for RAC in AWS is running the application on EC2, and Oracle RAC in a co-location facility or customer data center. AWS Direct Connect allows establishing private connectivity between AWS and data center/co location or customer data center to achieve the speed required. Datapipe is one AWS hosting provider partner that has done this:

Wednesday, March 20, 2013

Citrix has a number of virtualization solutions. XenDesktop and XenApp are two of them. The main difference between them is that XenDesktop has one individual desktop (and therefore own VM) only for each user and XenApp is a shared desktop model. The technical difference between the two is that XenApp is based on MSFT Terminal Services and hundreds of users can get virtual apps and desktops from a single VM. XenApp is fully supported by Citrix on AWS today.

Citrix XenServer (just like VMWare and MS Virtual Server) will not run on AWS/EC2. This is the case even though XenSever (as the name implies) is based upon the same open source kernel as AWS hypervisor.

Wednesday, March 6, 2013

This community software solution works to ensure MySQL databases deployed on AWS EBS volumes are keep in sync when snapshots are performed.https://github.com/alestic/ec2-consistent-snapshot, it flushes OS and some application caches to disk before creating EBS snapshots. It works on most *nix, it will also snapshot arrays of EBS volumes.

Standard Edition and Standard Edition One - EC2 instances with 4
or less virtual cores are counted as 1 socket, which is considered equivalent
to a processor license. For EC2 instances with more than 4 virtual cores, every
4 virtual cores used (rounded up to the closest multiple of 4) equate to a
licensing requirement of 1 socket. This means that running on m1.small, m1.medium, m1.large and m1.xlarge will all cost the same from an Oracle perspective. Details are: "When licensing Oracle programs with Standard Edition One or Standard Edition in the product name, the pricing is based on the size of the EC2 instances. EC2 instances with 4 or less virtual cores are counted as 1 socket, which is considered equivalent to a processor license. For EC2 instances with more than 4 virtual cores, every 4 virtual cores used (rounded up to the closest multiple of 4) equate to a licensing requirement of 1 socket. "The big difference between SE and EE are the number of sockets you can run on (and features/options that Oracle has turned on). This is not an issue with RDS instance types as the largest instance type has 8 virtual cores. This number of core is in line with the number of sockets (2 sockets) that is allowed for Oracle SE One(the license included option) per Oracle AWS licensing terms.